If you wanted a "one oil" for everything from Antarctica to the Sahara, in any petrol or light diesel engine, and probably most heavy diesels in a pinch, then 0W40 Mobil or Castrol would be the universal choice. It's not my favourite grade, but I can see why it's popular. If M1 wasn't $109 (Oz) for 5L, and was at US prices, it would likely be in my garage.